Hi everyone, I am new to this site and also relatively new to owning a sailboat. I bought my 1976 Islander 28 almost 2 years ago, and I have a question that only recently came up. The boat has an Atomic 4 gasoline engine.....being that it was original to the boat in 1976, does this mean that it should use LEADED gasoline? I have heard conflicting advice. I love my little boat and certainly do not want to damage the engine in any way. Can anyone answer this question? Thank you, Meg
Atomic 4 in my Islander
- Thread starter Song4sail
- Start date
- Status
Whats the 'rebuild' history of the engine?
The original A4 was built for leaded gasoline .... the lead 'plated' onto the valve faces/valve seats and acted as a cushion when the valve closed. You can add a "Re-Lead" compound to the gasoline. Re-lead compounds are still 'legal' for use in marine engines - boat chandleries and auto shops sell it. If the engine was rebuilt within the past 20 years most probably the valve seats were also changed to a 'hardened' seat and these can adequately be operated on a non-leaded gasoline. Since there is no catalytic converter, using a 're-lead' additive can be used if or if not the valve seats were changed. It all depends on the 'history' of the engine. ;-)
The original A4 was built for leaded gasoline .... the lead 'plated' onto the valve faces/valve seats and acted as a cushion when the valve closed. You can add a "Re-Lead" compound to the gasoline. Re-lead compounds are still 'legal' for use in marine engines - boat chandleries and auto shops sell it. If the engine was rebuilt within the past 20 years most probably the valve seats were also changed to a 'hardened' seat and these can adequately be operated on a non-leaded gasoline. Since there is no catalytic converter, using a 're-lead' additive can be used if or if not the valve seats were changed. It all depends on the 'history' of the engine. ;-)
Leaded fuel
My A-4 mechanic said to add one small container of marvel mystery oil per fill up (20 gallons of gas). He said it will save valve springs and make motor happy, nothing about additive for lead shortcomings. Go to A-4 website (or Moyer Marine, I believe) for more info.
My A-4 mechanic said to add one small container of marvel mystery oil per fill up (20 gallons of gas). He said it will save valve springs and make motor happy, nothing about additive for lead shortcomings. Go to A-4 website (or Moyer Marine, I believe) for more info.
Unleaded gas in atomic four
I own a Catalina 27' and I use the cheap unleaded gas in it with no problems. The Atomic 4 is a tough engine and can take a lot. It's also easy to work on. I wouldn't worry too much about the gas situation as I haven't had any problem with mine regardless what kind of gas to which I use.
I own a Catalina 27' and I use the cheap unleaded gas in it with no problems. The Atomic 4 is a tough engine and can take a lot. It's also easy to work on. I wouldn't worry too much about the gas situation as I haven't had any problem with mine regardless what kind of gas to which I use.
marvel mystery oil
I have a 1969 I-37 with an Atomic 4 and also just add marvel mystery oil to fuel. Have been doing this for my 3 years of ownership... Also, Jim I am at Dimillo's, 3I7 "Divided Sky"--stop by for a beer sometime. Cheers, Britt
I have a 1969 I-37 with an Atomic 4 and also just add marvel mystery oil to fuel. Have been doing this for my 3 years of ownership... Also, Jim I am at Dimillo's, 3I7 "Divided Sky"--stop by for a beer sometime. Cheers, Britt
- Status